JavaScript

Send and Receive WebSocket Frame

See more WebSocket Examples

Demonstrates how to send a websocket text frame to a websocket echo server. This example uses Chilkat's websocket test echo server at ws://websockets.chilkat.io/wsChilkatEcho.ashx

Note: The websockets.chilkat.io server imposes the following limitations:
Messages must be 16K or less, and each connection is limited to a max of 16 echoed messages.

JavaScript

var success = false;

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

var ws = new CkWebSocket();

// For brevity, this example does not check for errors when etablishing the WebSocket connection.
// See Establish WebSocket Connection for more complete sample code for making the connection.

var rest = new CkRest();
// Connect to websockets.chilkat.io
// IMPORTANT: websockets.chilkat.io accepts frames of up to 16K in size and echoes them back.
// IMPORTANT: The websockets.chilkat.io server imposes the following limitations: 
// ---------- Messages must be 16K or less, and each connection is limited to a max of 16 echoed messages.
success = rest.Connect("websockets.chilkat.io",80,false,false);
ws.UseConnection(rest);
ws.AddClientHeaders();
var responseBodyIgnored = rest.FullRequestNoBody("GET","/wsChilkatEcho.ashx");
success = ws.ValidateServerHandshake();
if (success !== true) {
    console.log(ws.LastErrorText);
    return;
}

// This example demonstrates sending a frame and receiving a text frame.

// Send a frame containing the string "Hello World!"
// This will be the first and final frame, and therefore this constitutes the entire message.
var finalFrame = true;
success = ws.SendFrame("Hello World!",finalFrame);
if (success !== true) {
    console.log(ws.LastErrorText);
    return;
}

// Read an incoming frame.
success = ws.ReadFrame();
if (success !== true) {
    console.log("Failed to receive a frame");
    console.log("ReadFrame fail reason = " + ws.ReadFrameFailReason);
    console.log(ws.LastErrorText);
    return;
}

// Show the string that was received.
var receivedStr = ws.GetFrameData();
console.log("Received: " + receivedStr);

// Close the websocket connection.
success = ws.SendClose(true,1000,"Closing this websocket.");
if (success !== true) {
    console.log(ws.LastErrorText);
    return;
}

// Read the Close response.
success = ws.ReadFrame();
if (success !== true) {
    console.log("ReadFrame fail reason = " + ws.ReadFrameFailReason);
    console.log(ws.LastErrorText);
    return;
}

// Should receive the "Close" opcode.
console.log("Received opcode: " + ws.FrameOpcode);
// Should be the same status code we sent (1000)
console.log("Received close status code: " + ws.CloseStatusCode);
// The server may echo the close reason.  If not, this will be empty.
console.log("Echoed close reason: " + ws.CloseReason);

console.log("Success.");